/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * License); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * AS IS BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

/*
 * Copyright (c) 2019, Open AI Lab
 * Author: haitao@openailab.com
 */

#ifndef __COMPILIER_FP16_H__
#define __COMPILIER_FP16_H__

#ifdef __cplusplus
extern "C" {
#endif


#ifdef __ARM_ARCH

#define fp16_to_fp32(data)	\
	({			\
    		float f=data; 	\
    		f;		\
	})

#define fp32_to_fp16(data) 	\
	({			\
	   __fp16 f=data;	\
	    f;			\
	})


#else

struct fp16_pack{
   unsigned short frac:10;
   unsigned char exp: 5;
   unsigned char sign:1;
} __attribute__((packed));

struct fp32_pack{
   unsigned int frac:23;
   unsigned char exp: 8;
   unsigned char sign:1;
} __attribute__((packed));

typedef struct fp16_pack __fp16;

static inline float fp16_to_fp32(__fp16 data)
{
   float f;
   struct fp32_pack * fp32=(struct fp32_pack *)&f;
   struct fp16_pack * fp16=&data;

   int exp=fp16->exp;

   if(exp==31 && fp16->frac!=0)
   {
      //return __builtin_inf()-__builtin_inf();
      fp32->sign=fp16->sign;
      fp32->exp=255;
      fp32->frac=1;

      return f;
   }

   if(exp==31)
       exp=255;
   if(exp==0)
       exp=0;
   else
       exp=(exp-15)+127;

   fp32->exp=exp;
   fp32->sign=fp16->sign;
   fp32->frac=((int)fp16->frac)<<13;

   return f;

}


static inline __fp16 fp32_to_fp16(float data)
{
   struct fp32_pack * fp32=(struct fp32_pack *)&data;
   struct fp16_pack  fp16;

   int exp=fp32->exp;

   if(fp32->exp==255 && fp32->frac!=0)
   {
      //NaN
      fp16.exp=31;
      fp16.frac=1;
      fp16.sign=fp32->sign;

      return fp16;
   }

   if((exp-127)<-14)
       exp = 0;
   else if((exp-127)>15)
        exp=31;
   else
        exp=exp-127+15;

   fp16.exp=exp;
   fp16.frac=fp32->frac>>13;
   fp16.sign=fp32->sign;

   return fp16;
}

#endif


#ifdef __cplusplus
}
#endif
#endif
